Answer to Question #92716 in General Chemistry for Efache

Question

Calculate the volume of hydrogen produced at s.t.p when 25g of zinc is added to excess dilute hydrochloric acid at 31 degrees celsius and 778mmhg pressure.

Answer 1

0.3846 mol                    X mol                      

      Zn + 2HCl = ZnCl₂ + H₂↑

   1 mol                         1 mol

n(Zn) = 25g / 65g/mol = 0.3846 mol.

n(H₂) = X = 0.3846 mol.

V(H₂) = n(H₂) × V_m = 0.3846 mol × 22.4 L/mol = 8.6150 L ≈ 8.62 L.